Information Technology IT – 14 Communications technology | e-Consult

A router operates at the network layer (Layer 3) of the OSI model. Its primary function is to forward data packets between different networks. It examines the destination IP address of a packet and uses routing tables to determine the best path to forward the packet towards its destination. Routers are commonly used to connect networks like a home network to the internet, or to connect different subnets within a larger organization. They operate based on logical addresses (IP addresses).

A switch operates at the data link layer (Layer 2) of the OSI model. It connects devices within the same network (e.g., a home or office network). Switches learn the MAC addresses of devices connected to their ports and use this information to forward data frames only to the intended recipient. This targeted forwarding improves network efficiency by reducing unnecessary broadcast traffic. Switches operate based on physical (MAC) addresses.

A hub is a simpler device that also connects devices within a network. However, unlike a switch, a hub broadcasts any data it receives on one port to all other ports. This means that all devices connected to the hub receive the data, regardless of whether it's intended for them. This broadcast nature can lead to network congestion and security vulnerabilities. Hubs operate at the physical layer and are generally considered obsolete in modern networks due to their inefficiency.

Key Differences:

• Layer of Operation: Routers (Layer 3), Switches (Layer 2), Hubs (Layer 1)
• Addressing: Routers use IP addresses, Switches use MAC addresses, Hubs operate at the physical layer.
• Data Forwarding: Routers forward packets between networks, Switches forward frames within a network, Hubs broadcast data to all ports.
• Efficiency: Switches are more efficient than hubs due to targeted forwarding. Routers are efficient for inter-network communication. Hubs are the least efficient.